Cell-balancing IC facilitates energy recuperation application design

January 29, 2015 //
By Christoph Hammerschmidt

The BD14000EFV-C from ROHM Semiconductor is a cell-balancing chip that helps reducing the size of electric double layer capacitors (EDLCs) in energy regeneration applications in hybrid electric vehicles and industrial equipment. The device also improves stability of such circuits as well as the operating life for EDLCs.

The chip integrates over 20 discrete components required for EDLC cell balancing on a single chip, reducing mounting area by 38% over conventional solutions while eliminating component variations, making it easier to configure compact, high reliability EDLC systems with up to six cells.

Multiple ICs can be connected in series to enable simultaneous control of even more cells. The cell balancing voltage can be set between 2.4V and 3.1V, ensuring support for a variety of EDLCs. Flag output is also built in, along with an over-current detection voltage function with adjustable detection voltage setting based on the cell balancing voltage. The chips is qualified for automotive use according to AEC-Q100.

Compared to other storage devices, EDLC offers faster charge/discharge performance, longer life, and greater safety while minimizing environmental impact, making it the solution of choice for a variety of applications including automotive and industrial systems.
When connecting multiple EDLCs in series to support higher voltages, the voltage applied to each EDLC cell may vary, which can adversely affect the lifetime and shorten the amount of time they can be safely used. Up to now cell balancing operation has been achieved through discrete configurations, making it necessary to address a number of issues such as board space and design load in order to minimize fluctuations while maintaining reliable cell balancing operation.